1. Field of the Invention
The present invention relates to a data processing apparatus and method for processing discrete data arranged at predetermined time intervals.
Specifically, this invention relates to a data processing apparatus, etc., capable of redefining resolution and reproducing data to a necessary band. In this invention, the data processing apparatus individually adds a first derivative to a plurality of N-bit discrete data arranged at first time intervals. When one or a plurality of discrete data interposed between two discrete data can be approximated by a curve which passes through the two discrete data and is generated on the basis of the discrete data, the first derivative, and the time interval information, the data processing apparatus deletes one or a plurality of the discrete data, and generates a plurality of discrete data having heterogeneous time intervals, the additional first derivative and the time interval information. After that, the data processing apparatus generates a curve passing through the two discrete data generated on the basis of the two consecutive discrete data, the discrete data, a first derivative, and time interval information using a plurality of the discrete data, and obtains a plurality of M-bit discrete data arranged at second time intervals on the basis of each curve.
2. Description of the Related Art
The bandwidth of discrete data can be improved by increasing the sampling frequency of the discrete data. However, if the signal components using the band defined there are really few, similar signals are sampled many times, and thus there has been a problem in that it is inefficient for storing the data into a medium, such as a memory, etc., for example.
Also, when an attempted is made to output data with higher resolution than input data, for example it is necessary to pass the data through a band-limitation filter, etc. In order to obtain a smooth characteristic, it becomes necessary to impose a strong band limitation. Thus, there has been a problem in that the high-frequency components originally held by the data are dropped.
For example, Japanese Unexamined Patent Application Publication No. 06-90358 has disclosed a data compression method in which one or a plurality of discrete data interposed between two discrete data (data sample) can be approximated by an approximate line (straight line), and one or a plurality of the discrete data is removed in order to compress the data.